Impulse-control system.



A. E. LUNDELL.

IMPULSE CONTROL SYSTEM.

APPLICATION FILED MAY 25. I916.

Patented Oct. 2, 1917.

)M A. A Z n w). m5 w A b ALBEN E. UN' ELI or new YORK, 1\T.-Y., nssreuonTo WESTERNEELECTRICI COMPANY, INCORPORATED, OF'NEW' Y0ItK,-1 T. Y2,Axconronarro tor nnw YORK.

IMPULSE-CONTROL SYSTElVL 4 To an whom it may concern:

Be it known that I', ALBEN E. LUNDELL, a citizen of the United States,residing at New York, in the countyfof Bronx and State of New York, haveinvented certainnew and pulse control systems'for selector switches inautomatic telephone exchanges.

The lines and ltrunks in automatic telephonesystems beingarranged ingroups, the I automatic selector switches are equipped with means forprimarily selecting a desired group and then for selecting, during asecondary movement, an idle line in the selector *rciu'p. The primarymotion of the switch 18 controlled by an, impulse mechanism, and inorder toinsure the change-over from the primary operationof the switchto the secondary operation, a timing device, such as a slow-actingrelay,ris'provided inassociation with the switch. Thisrelay does notrespond -to the operations of the primary impulse receiving meansassociated with the selector, but becomes actuated uponthecessationofthe primary impulses, andf causes the switching out of the, primary'andthe switching in of theflsecondary [operating means? V v V t It is theobject of this inventionctorprovide an, impulse controlling system inwhich thenecessity ,of providing sucha timing device for controlling thechange-over from the j'prima'ry to the secondary operation ofthej'selector switch, is obviated.- .Y

' With this 'object in view this invention provides a system in whichthe" electromag netic means controlling the I primary 5 opera-- tion ofthe selectorswitch is conductively associated Withthe impulse circuit,and the electromagnetic means controlling the] sec ond liy operation ofthe selector switch is inai tively united? with but. ,conductivelySepara ed vfr i mrirr "Figural is a diagram 'matic' v phoneexchangesystem embodying the presentfinventiom only so much being shownof thefbircuits iland c apparatus as is necessary foria' clearu'nder'st'anding'of thepresent invention.

iew of aftele Specification of Letters IPatent. Patented Oct 2, 191 7; 1Application filed May 25, 1916. Serial No. I i

rent changes; produced the impulsesendlvngljclrcuvlt'vl A YThe'calll'ng.dev1ce, 'by'meansof which an impulse receiving relay 10and'ia 'changeover relay '12 maybe controlled, is'rfe'pre sented at 11.The callingjdevice' comprises a "dial "1'13, provided with a pluralityoffingenholdsi 14', by means Qf-Whichi the dial may'be'fmove d towardcafstationarylstop 15.

Upon the' release ofthe' diaha motor'spring,

(notfshown) wound during the forward movementfof the" same, causes thereturn of the dial, and during this return movement,

aip'a wl 16, pivoted on an; arm 17 of dial 13 engages the ratchets of aWheel 18 and causes t to rotateWith the dial. The ratchet a wheel :18,throughthe agency, of a gear wheel 19, causes an armQO to travel over acommutator 21 in the direction indicated by the arrow, theTatio betweenthe movement of the arm 20 and the dial 13 being'such that for eachfinger-hold by which the dial l8 has been displaced, the arm 20will'perform onecompleterevolution; The dial is sojadjustedthataninsulated lug 24 on member 17causes the closure'pf a contact 25prior to. t e g ment pf. Se men O mutator2l, by anti 20. Upon theremovalof the receiver from the switchhoolg at; 'substation 27, acircuit is closed f roml grounded battery through the windingof relay10, the primary winding. of

an indulction'coilj28, aside sw-itchwip'er 29, conductor 30," thesubstation circuit, conductor 31, contact. 25, conductor 32, and aside-'switch'wiper 33 to ground Due to the infinitely high kresistanceof this circuit prior to its closure, no current is flowing in thesame." :Upon'thesudden closure of the circuit at thepontacts', of thehook switch, the 'esi'stanc e' ofthe; circuit will he suddenly reld d,ei ldfthe; surge of current thus prodill d in. the circuit, will causethe induction bffs uifisient""current through the secondary W nding-1' knductie T1 10 2 c use th energization ofrelay 12 g 'lhejresistance ofhis u se ir fb ma ntai ed t am p int, .ithwmou Of 'cilrltsntf owi initlfifs time willme mainth a116,: an

the; op ning 10 s u'itrq u th witch wiper to move-into position Thesechanges of current in the circuit are indicated in Fig. 2, to the lefthand of a dotted line 35.

The calling subscriber now inse-rts his finger into the finger-hold 1%,representing the desired number of digits, and moves dial 13 until hisfinger reaches the stop 15. When the lug 24- disengages spring 36,contact 25 is opened. The above traced circuit, however, remains closedthrough conductor 37, segment 26 of commutator 21,

7 46 into the impulse sending circuit, causing thus, the gradualreduction of current in this circuit until a segment 17 is reached, whenthe circuit is opened, and thus the current flowing therein is zero. Arm20 then continuing its rotation, includes into the circuit decreasingportions of resistance 46. through segments 18, causing the grad ualincrease of current in the impulse sending circuit. The wavelilrechanges of cur rent, which are represented in'Fig. 2between dotted lines35 and 49, are gradual,

and therefore the current induced into the ci'rcuit of relay 12 will notbe of sufficient strength to energize this relay.

lVhen the current reached a sufficiently low value, relay 10 becamedeenergized and opened the circuit of a primary magnet 50, which causedthe stepping of the wipers of a selector 51 in a primary direction. Thisoperation of sender 11, relay 10 and magnet 50 will be repeated as manytimes as predetermined by the number of digits selected and when thecurrent in the impulse sending circuit reaches the zero point for thethird time, arm 20 being in engagement with segment alarm 17 of dial 13engages spring 86 and causes the closure at contact point 25 oftheoriginally traced circuit of relay 10, producing a sudden change of 'resistance, which will result in. the induction of suflicient current inthe circuit of relay 12 for operating the same. Arm 20 returns to itsnormal position without causing any further efiect on the impulsesending circuit. Upon thede'e'nergization of relay 12, which shortlyfollowsits energization, sideswitch magnet 84. again becomesdeenergized, and by moving the side-switch wipers into position 3,causes the connection, of an' interrupter in circuit with a secondarymagnet 71, which controls a secondary or trunk-hunting motion ofselector switch 51.

While a test wiper. 72 is traveling over grounded, e. busy, terminals,side-switch magnet 3 1 will be maintained energized, and when an idleterminal is reached, this magnet becomes deenergized and moves thesideswitch wipers into position 4, disconnecting, thus, the secondarymagnet and connecting conductors 30 and 32 to the wipers of selector 51.

. Upon the termination of the conversation, an impulse is sent throughwiper 7 2, conductor 75 and the winding of a release magnet 76 foroperating the same. The release magnet causes the restoration ofselector 51 and the associated side switch. 77 is an offnormal contactof selector 5L During the as applied to a telephone system in which theselector switches are controlled under the directive control ofanimpulse-sending device, it will be obvious to those skilled in the artthat it is applicable to impulsesonding systems of widely varyingcharacter, such as revertive-impulse systems, in which the selectorrather than the impulse device causes'the sending out of impulses. Itwill be further apparent that instead of an induction coil, otherwell-known apparatus, such as a condenser, may be employed forinductively connecting but conductively separating the relay 12 and theimpulsesending circuit.

Vhat is claimed is: I

1. In a telephone exchangesystem, [an incoming line and groups ofoutgoing lines, a selector switch, an impulse sender associated withsaid incoming line, means con trolled by said impulse sender forproducing wave-like current fluctuations in said in coming line, meansresponsive to said current fluctuations for causing said selector toselect a desired group of outgoing lines, means controlled by saidimpulse sender for producinga sudden change of resistance in saidincoming line, and 1neans operative thereupon for causing said selectorto hunt for an idle line in said selected group ofout gomg lines. o

2. In a telephone eXchange'system, a I- i in coming line andgroups ofoutgoing lines, a

selector switch, an ele'ctromagnetic means for controlling said switchto select a group of outgoing hnes, another electromagnetic 7 Copies ofthis patent may be obtained for means for controlling said switch toseize a line in the selected group, switching means for controlling thesuccessive operation of said electromagnetic means, a relay inductivelyassociated With said incoming line,

means. operable through said incoming line line and operabletherethrough for control-' ling said selector to seize a group ofoutgoing lines, and another electromagnetic means inductively associatedwith said incoming line and operable therethrough for causing saidselector to hunt for an idle line in the selected group of outgoinglines.

4. In a telephone exchange system, a plurality of subscribers stations,a selector switch arranged to establish a connection from one of saidstations toward another station in accordance with the group and linedesignation of said latter station, a cir-.

cuit extending from the calling station to said selector switch, a relayincluded in said circuit for controlling the group selecting operationof said selector, and a relay inductively connected to said circuit andoperable tlierethrough for controlling the line selecting operation ofsaid selector.

5. In a telephone exchange system, a calling and a called station, aselector switch arranged to perform a primary and a secondary operationto interconnect said sta-v tions, a circuit between said calling stationand said selector, electromagnetic means included in said circuit forcausing the primary operation of saidselector, and anotherelectromagnetic means inductively Connected to said circuit and operabletherethroughfor controlling the secondary operation of said selector.

6. In a telephone exchange system, two telephone stations, a selectorswitch'for interconnecting said stations, electromagnetic means forcontrolling a primary operation, and another electromagnetic means forcon-' trolling a secondary operation of said selector switch, a circuitextending from the calling station to said selector, means for producingwave-like current changesand means for producing sudden changes ofresistance in said circuit, means for operating 7 said first mentionedelectromagnetic means in accordance with the wave-like current changesproduced in said circuit, and means for operating said second mentionedelectromagnetic means in accordance with the sudden changes ofresistance produced in said circuit.

7 Incombination, a selectively operable switch adapted to perform aprimary and a secondary motion, a controlling circuit forv said switch,an electromagnetic means at said switch for controlling said primarymotion conductively connected to said circuit, and anotherelectromagnetic means at said switch for controlling said secondarymotion inductively connected to said circuit.

In witness whereof, I hereunto subscribe my name this 24th day of MayALBEN E. LUNDELL.

Washington, D. G.

five cents each, by addressing the Commissioner of Patents,

